The mouse phenotyping core will provide expertise and training in the characterization of rodent models of diabetes. To achieve this mission, the Core will provide assistance in the histopathological characterization of mouse models of diabetes and training in the performance of basic metabolic assays, such as glucose and insulin tolerance tests. The Core will also provide consultation on the proper approach to generating recombinant and inbred strains of transgenic and knockout mice, and interact with the Genomics Core to help investigators design appropriate genotyping strategies for genome scans. In addition, the Core is in the process of developing expertise in performing glucose clamp studies to investigate whole body and organ-specific metabolic parameters. Through collaborative efforts with the other Cores of the proposed DERC, the effects of defined genetic alterations in rodents can be thoroughly characterized for their effects on metabolism, ingestive behavior, energy balance, body composition, and endocrine function. The Core will serve an important training and education function for many DERC investigators by providing advice on how to prevent common mistakes in breeding programs.